GaInNAs: a novel material for long-wavelength semiconductor lasers

TLDR

GaInNAs, introduced in 1995, can be pseudomorphically grown on GaAs to form deep type‑I quantum wells with a bandgap of 1.3–1.55 µm, suppressing high‑temperature electron overflow and offering superior temperature stability for long‑wavelength laser diodes. The study systematically investigates the optical and physical parameters—quantum efficiency and gain constant—to confirm GaInNAs’s suitability for optical‑fiber laser diodes. GaInNAs was grown by gas‑source molecular beam epitaxy using a nitrogen radical, and its key parameters were measured to assess laser performance. GaInNAs enabled edge‑emitting lasers with record room‑temperature CW operation (T₀ = 126 K) and VCSELs that achieved room‑temperature CW lasing at 1.22 µm with a low threshold.

Abstract

GaInNAs was proposed and created in 1995 by the authors. It can be grown pseudomorphically on a GaAs substrate and is a light-emitting material having a bandgap energy suitable for long-wavelength laser diodes (1.3-1.55 /spl mu/m and longer wavelengths). By combining GaInNAs with GaAs or other wide-gap materials that can be grown on a GaAs substrate, a type-I band lineup is achieved and, thus, very deep quantum wells can be fabricated, especially in the conduction band. Since the electron overflow from the wells to the barrier layers at high temperatures can he suppressed, the novel material of GaInNAs is very attractive to overcome the poor temperature characteristics of conventional long-wavelength laser diodes used for optical fiber communication systems. GaInNAs with excellent crystallinity was grown by gas-source molecular beam epitaxy in which a nitrogen radical was used as the nitrogen source. GaInNAs was applied in both edge-emitting and vertical-cavity surface-emitting lasers (VCSELs) in the long-wavelength range. In edge-emitting laser diodes, operation under room temperature continuous-wave (CW) conditions with record high temperature performance (T/sub 0/=126 K) was achieved. The optical and physical parameters, such as quantum efficiency and gain constant, are also systematically investigated to confirm the applicability of GaInNAs to laser diodes for optical fiber communications. In a VCSEL, successful lasing action was obtained under room-temperature (RT) CW conditions by photopumping with a low threshold pump intensity and a lasing wavelength of 1.22 /spl mu/m.